Improvement in let-off mechanism for looms



nitml (Staten l ERASTUS BRIGHAM BIGELOW,\OF BOSTON, MASSACHUSETTS.

Lette/rs Patent N o. 103,415, dated May 24, 1870.

IMPROVEMENT IN LET-OFF MECHANISM FOR LOOMS.

The Schedule referred to in these Letters Patent and making part of the sam'e.

I, ERASTUS BRIGHAM BIGELoW, of-Boston, in the county of Suiolk and State of Massachusetts, have invented certain Improvements in Let-olii Mechanism for Power-Looms, of which the following is a specification.

In my patent of the 9th of February, 1869, No; 86,805, I have described and claimed a spring'arrangement, combined with a vibrating roller, or its equivalent, for regulating the delivery of the warps, whereby the tension of the wai-ps is gradually diminished while the open shed is being formed, and gradually increased to an extent to resist the beat-up while the `shed is being closed, a single mechanism being employed for producing tension ofy the warps, both in the open shed and in resisting the beat-up.

I nd that a separate device.` for accomplishing each of these'objects, though acting together, produ ces a good result, and is capable of more easy adjustment.

The annexed drawing represent-s my present invention, and such parts of'a loom as are necessary to show its application.

i Figure`1 is a left-hand end elevation; Figure 2 a transverse section, looking toward the left, and

Figure 3 is a plan.

The frame of the loom is marked a, the lay l, and' thelay-shaft c.

' The vibrating rollerorhar, the varying position of which regulates the .delivery of the warps, is marked d,

The warps, which are indicated by a line, e, pass from the warp-beam over the vibrating roller or bar d to the cloth-forming line, as is usual, the cloth being takennp by a. positive motion.

Tbifmode of operating the warp-beam, and of counecting it with the vibrating roller or bar for regulating the delivery of the warps-being well understood, I have not deemed it necessary to represent them in the drawings.

-The vibrating roller or bar d is supported by bent levers, f, one on either end of the loom. which oscil- Vlate on axis g, and-engage with pinions h, affixed to a the spring or weight being suihcient to give the needed tension to the warps when the shed is open.

This degree of tension, however, except in weaving very light fabrics, is not suiicient to resist the beating np of the cloth by the lay, and another deviceis employed to increase the tension of the warps at the time ofthe beat-up, which I will now describe.

A spring lever-arm, on, turns loosely on the tension-shaft i, and has its lower end connected with thelay b, by a connecting-rod, n, and vibrates in unison with it. l

As the `lay advances to beat up the cloth, the spring lever-arm m strikes against a stop, o, atixed to the pulley j, andturns the tension-shaft t in the direction to tighten the warps, and thus gradually increases their tension to'a degree to resist the beat-up, and when the lay falls back it gradually relaxes the spring lever-arm, and diminishesthe tension of the warps, until the force of the spring or weight l is applied to them.

It is important to note, in this connection, the relation of the spring or weight l and the spring leverarm' 'm to the regulation bf the delivery of the warps'1 as only the spring or weight Z governs the position of the vibrating roller or bar d, when it determines the action of the let-oli` mechanism, the spring lever-'arm m at that time being thrown back far enough to clear the stop o, and thus have no action on the tensionshaft l The stops 0,'01 the connecting-rod n, may be made adjustable for the convenient adaption of the force of the'spring lever-arm m to the requirements of the cloth to he woven, heavy goods requiring more force to resist the beat-up than light goods.

The spring action of the spring lever-arm 4m is only required to adapt the strain it gives to the warps at the time ofthe beat-up to their varying condition, consequent upon the varying action of the delivering mechanism, and except-at, or nearly at, the time ot' the beat-up, the spring lever-arm acts as a lever, increasing or diminishing the tension of the ivarps by themotion imparted to it by the lay.

A modified arrangement of the vibrating bar or roller d, and the devices for giving tension to the warps, is represented in gs. 4 and 5.

- Instead of supporting the vibrating bar or roller d by oscillating lever-arms, actuated by pinions aixed to a tension-shaft, as above described, it may be supported by arms extending from an oscillating. shaft,p, as shown in g.4.

In this arrangement the tensionshaft i may be dispensed with, and the pulley j, and spring devices connected therewith for giving tension to the warps, may

be-supported by, and oscillate on a stud, g.

Having described my invention, and pointed out some of the modifications of which it is susceptible without departing from its 'distinguishing principles,

What I claim as new, and desire to. secure by Lei;-

`ters Patent, is-

Combining a vibrator, and mechanism for operating it, controlled by a spring or equivalent, toproduce the Y necessary tension on the warp when the shed is made, l

HERBERT T. WHITMAN, ELIzA F. BIGELOW. 

